New studies show that the volcano’s underground magma system is larger than previously measured and may extend outside the known caldera boundaries. The estimated total volume of magma down there, scientists say, is around 48-144 cubic miles (200-600 cubic km) – much more than earlier estimates. However, it’s 85% to 95% solidified and so very difficult to erupt. The Yellowstone Volcano Observatory says these new findings do not mean increased geologic hazard at the volcano and don’t increase the chances of a supereruption in the near future.
Higher than normal ground temperatures and increased thermal activity force the closure of several trails for visitor and employee safety. Yellowstone Volcano Observatory scientists deploy a network of seismographs, GPS receivers and thermometers, making Norris the most heavily studied geyser basin in the world.